Expressions are a common element of SQL statements( statements are select, delete and update).
they often occur in the where clause of select, delete & update.
For Example:
DELETE FROM users WHERE id=5;
Here id=5 are expressions.
Following are the different components of SQL Expression:
Following are the different components of SQL Expression:
- Numeric Expressions
Exact value Literal are: 11,12.33, 44.333
Approximate Literal are 1233E2, 44333E3
Operations on decimal value have precision upto 64 digits, currently its 30 character.
In Approximate, mantissa allows upto 53 bit of precision which is about 15 decimal digits. - String Expressions
String like 'sql' or mysql - Temporal Expressions
It include dates, times and datetime values like Select ‘2012-01-01’ + interval 10 day
- Functions like current(), version(), avg(), sum()
- Regular Express (Regex)
